Add Code Metadata rule to soong/testing.

This Cl adds a new rule to Soong to generate code ownership metadata. Also, this CL adds a provider in the Java SDK library to provide generated source files to the Code_metadata rule. Will add providers to other libraries in the future changes.

Bug: 296873595
Change-Id: Ic2e43aa9b161231fea4416d1f0d36b778361d7c5
diff --git a/java/sdk_library.go b/java/sdk_library.go
index fbfe509..4eaa382 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -1477,6 +1477,7 @@
 		}
 	}
 	ctx.SetProvider(android.AdditionalSdkInfoProvider, android.AdditionalSdkInfo{additionalSdkInfo})
+	ctx.SetProvider(android.SrcsFileProviderKey, android.SrcsFileProviderData{SrcPaths: module.uniqueSrcFiles})
 }
 
 func (module *SdkLibrary) AndroidMkEntries() []android.AndroidMkEntries {